Improvement in lead-furnace bottoms



T. BISCH.

LEAD FURNACE BOTYTOMS. N0.189,016. Patented Apri 13.1877.

UNITED STATES PATENT OFFICE.

THEODORE BISOH, OF DE SOTO, MISSOURI.

IMPROVEMENT IN LEAD-FURNACE BOTTOMS.

Specification forming part of Letters Patent No. 189,016, dated April 3,1877; application filed October 28, 1875.

a To all whom it may concern sole of an air-furnace is reduced at a low heat,-

and always without fusion, there'is nevertheless a considerable quan tity of silicious matter injuriously combined with the lead oxide formed, causing a reduced yield from even pure galena.

Slag bottoms, from unavoidable conditions, are used almost exclusively, lead slag being the best material that lead-smelters can easily procure, it being also already partially saturated with lead or other metals and oxides.

Another expensive attendant is in the constant need of repair from corrosion or abraslon.

My invention is only applicable to dry reduction, since the heat at which galena can be reduced in air-furnaces is so much under that at which iron actively absorbs sulphur, that the iron sole has no durable quality lost thereby.

From a practical use of air or ell furnaces for fifty years with slag bottoms, and a short experience with an iron bottom, I find that the iron bottom saves time, labor, and fuel, and afiords a superior yield and quality of lead, leaving a residue or slag that is only silicated by the ore impurities, the yield being furnace to keep the metal hot; S, front stir- I ring-door. The pot P when in position has its lip seated in a cut-away in the under side of the sole-plate, to secure the delivery of the metal over its edge without leakage.

I do not claim an iron sole-plate as used in a boiling-furnace.

1 claim In combination, the cast-iron furnace-sole, inclined from rear to front, and having its upper surface longitudinally synclinal, and the metal-discharging pot, the sole being suitably cut away at its discharge end to receive the pot, and form therewith a drip-proof seat, all substantially'as and for the purpose herein set forth.

THEO. BISGH.

Witnesses:

A. M. TYLER, R. BURROUGHS. 

